cis-ubuntu1604-v200-5-4-1

name	cis-ubuntu1604-v200-5-4-1
description	Ensure password creation requirements are configured
category	cis-iam
version	2.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-16.04","authentication","pam"]
cis_id	5.4.1
cis_benchmark	CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

Ensure password creation requirements are configured

Profile Applicability:

• Level 1 - Server
• Level 1 - Workstation

Assessment Status: Automated

Description

The pam_pwquality.so module checks the strength of passwords. It performs checks such as making sure a password is not a dictionary word, it is a certain length, contains a mix of characters (e.g. alphabet, numeric, other) and more. The following are definitions of the pam_pwquality.so options.

The following options are set in the /etc/security/pwquality.conf file:

• Password Length:

  • minlen = 14 - password must be 14 characters or more

• Password complexity:

  • minclass = 4 - The minimum number of required classes of characters for the new password (digits, uppercase, lowercase, others)

  OR

  • dcredit = -1 - provide at least one digit
  • ucredit = -1 - provide at least one uppercase character
  • ocredit = -1 - provide at least one special character
  • lcredit = -1 - provide at least one lowercase character

The following is set in the /etc/pam.d/common-password file:

• retry=3 - Allow 3 tries before sending back a failure. The settings shown above are one possible policy. Alter these values to conform to your own organization's password policies.

Rationale

Strong passwords protect systems from being hacked through brute force methods.

Audit Procedure

Command Line

Verify password creation requirements conform to organization policy. Run the following command to verify the minimum password length is 14 or more characters:

grep '^\s*minlen\s*' /etc/security/pwquality.conf

Expected output:

minlen = 14

Run one of the following commands to verify the required password complexity:

grep '^\s*minclass\s*' /etc/security/pwquality.conf